The present invention relates to a plane light source device and a display device provided with the same, more particularly to a plane light source device used for a backlight of a display device such as a transmissive-type liquid crystal or the like, and to a display device using this plane light source device.
Japanese Unexamined Patent Publication No. 258764/2002 discloses one example of a conventional plane light source device. As shown in FIG. 1 of the above-mentioned publication, this plane light source device reflects light emitted from a light-emitting diode 2 toward light distribution means 1 having a light scattering function with reflection means 3 that is arranged to be inclined, and the reflected light is scattered at the light distribution means 1, thereby forming surface-like illumination light.
The plane light source device disclosed in Japanese Unexamined Patent Publication No. 258764/2002 uniformly reflects light from the light-emitting diode 2, arranged at the edge section, toward the light distribution means 1 by the reflection means 3, so that the illumination light has high brightness in the vicinity of the light-emitting diode 2 but has reduced brightness as it is away from the light-emitting diode 2, thus being non-uniform. When the illumination light of the plane light source device is non-uniform as described above, the displayed image has non-uniform brightness or non-uniform chromaticity, thereby entailing a problem of deteriorating an image quality.